Lesson Overview
In this lesson, students will explore what makes circles special, learn about the parts of a circle, such as the radius and diameter, and discover the properties of circles.
The most exciting part is using Ziggy to draw perfect circles by turning it a full 360 degrees.
What You Will Learn
• Understand the concept of a circle
• Identify and describe the parts of a circle
• Learn the properties of circles
• Draw circles using the turtle robot
Exploring Circles in Geometry
A circle is a round shape that:
• Has no corners
• Has no straight edges
• It is made of points that are all at the same distance from the centre. This distance is callefdasfdsad the radius.
Circles Around Us
Many objects around us have a circular shape, such as:
• Wheels
• Plates
• Clocks
• Coins
• The Sun
Parts of a Circle
1. Center
The center is the middle point of the circle.
2. Radius (r)
The radius is a line segment that connects:
• The center of the circle
• Any point on the circle
Symbol: r
3. Diameter (d)
The diameter is:
•
A line segment with both ends on the circle
•
It passes through the center
•
It is twice the radius
Formula: d = 2r
4. Circumference
The circumference is:
• The distance around the circle
• The perimeter of the circle
Properties of Circles
• All points on the circle are equidistant from the center
• The diameter divides the circle into two equal halves
• The diameter is the longest chord
• Diameter = 2 × radius
• A full circle is divided into 360 degrees
Activity: Drawing a Circle with Ziggy
Since a circle has 360 degrees, Ziggy can draw it by:
• Moving forward a little
• Turning slightly
• Repeating the steps
Method 1: Small Steps
• Pen down
• Move forward 1 step
• Turn left 1°
• Repeat 360 times
• Pen up
Method 2: Bigger Steps
• Pen down
• Move forward 10 steps
• Turn left 10°
• Repeat 36 times
• Pen up
Try to change the step distance. What do you notice?
Challenge
Draw a Happy Face
Try to draw:
• A big circular face
• Two small circles for eyes
• A curved smile
Be creative!
